The present invention relates to method and apparatus for automatically packaging stockings, and more particularly to a fully automatic system for enclosing stockings, such as seamless stockings and panty-hoses, folded around a cardboard insert in an envelope of transparent, thermoplastic material.
Although the following descriptions are focussed upon application of the present invention to stockings only, the present invention is more generally applicable to packaging of substantially flat, relatively long, non-rigid and foldable articles.
Reverting to the application to stockings, one cycle of packaging process roughly includes the step of placing stockings in position on an operating station, the step of feeding an insert in position on the stockings so placed, the step of provisionally fixing the position of the insert relative to the stockings, the step of folding the stockings around the insert, the step of feeding an envelope to a prescribed stand-by position with its mouth open, the step of conveying the stockings folded around the insert to a prescribed position in line with the envelope in the stand-by position, the step of enclosing the stockings with the insert in the envelope, and the step of sealing the envelope.
Several systems have been proposed in order to achieve such an automatic packaging of stockings, but they are all common in their basic operational construction. First, each system includes a plurality of folding steps. Secondly, these folding operations have to be carried out during transportation of stockings. These naturally causes complicated mechanical construction of the apparatus and naturally difficulty in maintenance and adjustment, thereby raising production cost greatly.
When folding is to be carried out concurrently with transportation of stockings, it is necessary to compulsorily feed the stocking into a nip or nips formed by at least a pair of conveyer belts or slide rollers in pressure contact and such strong nip tend to develop defects such as distortion, thereby seriously damaging commercial value of stockings which generally require fine, soft and smooth touch.
For these reasons, stockings have conventionally been mostly packaged by manual operation. Even in a better case, stockings have to be folded around an insert by manual operation before supply to an automatic packaging machine as a typical example is disclosed by Japanese Patent Publication No. Sho. 50-22477.
In anyway, at least the first four steps of the abovedescribed one cycle of packaging process have to depend upon manual operation, which naturally leads to inevitable rise in labour cost. Further, the relatively low production efficiency in the packaging process caused by inclusion of large ratio of manual labour forms a serious bottleneck in stream lining the entire, continuous production system of stockings. Thus, reduction in manaual labour in packaging process has in particular been desired by producers of stockings.
An insert to be folded around by stockings is not limited to a flat one. That is, a foldable insert is made up of a back cover section, a front cover section and an insert section bordered by two bending edges. The insert section is folded around by the stockings as an ordinary insert, the back cover section covers the back side of the stockings folded around the insert section, and the front cover section covers the front side of the stockings folded around the insert section and is usually accompanied with advertising or other descriptive representations.
When such a foldable insert is used, the insert has to be once flattened, or opened, prior to being placed in position on stockings. Next, such an open insert has to be placed on the stockings so that its insert section is placed about middle of the stockings. After the correct placement is complete, the stockings are folded around the insert section of the foldable insert as in the case of an ordinary flat insert. Finally, the front and back cover sections have to be folded around the stockings which have already been folded around the insert section.
Due to the complication of the work, the process has to be generally carried out by manual labour only which requires high technique and time consumption. Consequently, use of foldable inserts conventionally seriously hindered full automization of the stockings packaging process, and greatly lowered overall efficiency of the process, too.
The low process efficiency in packaging stockings has also been caused by manual sealing of an envelope enclosing folded stockings with an insert.
After the stockings are enclosed in the envelope, its mouth is still left open and its flap still remain flat. In order to seal the envelope, an operator needs to fold over the flap and apply one or more gummed tapes which hold the flap down. Further, requirement for correct positioning of the tapes and extremely frequent repetition of the work caused increased fatigue of the operators and difficulty in long, continuous service.
Process efficiency in automatic stockings packaging is greatly swayed by the type of the pattern of stockings folded around an insert. After the folding, the stockings with the insert have to be enclosed in an envelope placed in the stand-by position with its mouth open.
In the conventional type, the toe or waist end is exposed outside the stockings in the folded state. That is, the uppermost layer of the folded body always includes either of the toe and waist ends. Presence of such an end on the upper most layer often disables smooth entrance of the folded stockings into the envelope through its open mouth, and naturally enclosing ends in failure.